From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <4EC3EFB3.9080205@metafoo.de> Date: Wed, 16 Nov 2011 18:15:31 +0100 From: Lars-Peter Clausen MIME-Version: 1.0 To: Mark Brown CC: Dimitris Papastamos , Jonathan Cameron , Michael Hennerich , linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, device-drivers-devel@blackfin.uclinux.org, drivers@analog.com Subject: Re: [PATCH 5/7] regmap: Check if a register is writable instead of readable in regcache_read References: <1321457302-8724-1-git-send-email-lars@metafoo.de> <1321457302-8724-5-git-send-email-lars@metafoo.de> <20111116161631.GK29986@opensource.wolfsonmicro.com> <4EC3E619.70503@metafoo.de> <20111116163812.GM29986@opensource.wolfsonmicro.com> <4EC3EA61.2000705@metafoo.de> <20111116165622.GP29986@opensource.wolfsonmicro.com> <4EC3EE32.2090007@metafoo.de> <20111116171213.GR29986@opensource.wolfsonmicro.com> In-Reply-To: <20111116171213.GR29986@opensource.wolfsonmicro.com> Content-Type: text/plain; charset=ISO-8859-1 List-ID: On 11/16/2011 06:12 PM, Mark Brown wrote: > On Wed, Nov 16, 2011 at 06:09:06PM +0100, Lars-Peter Clausen wrote: >> On 11/16/2011 05:56 PM, Mark Brown wrote: > >>> No, really - just do something legible and robust. For example, teach >>> regmap_readable() about the cache. > >> Doesn't make much sense. We call regmap_readable from regcache_read, which >> is only called if we use a cache. So if we let regmap_readable return true >> in case we use a cache it will always be true in regcache_read and we can >> drop the check entirely. > > We should at least check that we actually have a cached value there - > the cache is sparse after all. That's what the cache already does today, you recently change the rbtree implementation to return -ENOENT if there is no cached value.